Please make sure to apply the filter (rule) for the secondary list lookup ID.
It can be done by following steps (high level) :
- Add rule for the property and select set field value
- In the rule detail you have to select the field value (destination)
- In the value field, you have to map the source and destination lookup field values to apply the filter like below :
xdXDocument:GetDOM("DatasourceName")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:Engagement_x0020_PMM/pc:Person/pc:AccountId[../../../d:PMOPMM/pc:Person/pc:AccountId = xdXDocument:get-DOM()/dfs:myFields/dfs:dataFields/my:SharePointListItem_RW/my:Portfolio_x0020_PMM_x0020__x0028/pc:Person/pc:AccountId]
xdXDocument:GetDOM("DatasourceName")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:Engagement_x0020_PMM/pc:Person/pc:AccountId[../../../d:PMOPMM/pc:Person/pc:AccountId = xdXDocument:get-DOM()/dfs:myFields/dfs:dataFields/my:SharePointListItem_RW/my:Portfolio_x0020_PMM_x0020__x0028/pc:Person/pc:AccountId]